Sudden Infant Death Syndrome (SIDS) has been defined as the "sudden death of an infant under one year of age which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and a review of the clinical history." SIDS occurs in all types of families and is generally independent of race and socioeconomic level. It is unexpected and usually occurs in apparently healthy infants from one month to one year of age. Death occurs without warning and is accompanied by no signs of suffering. Five to six thousand infant deaths per year were attributed to SIDS during the late eighties and early nineties.
The horror of SIDS, also commonly known as "crib death", lies in the thus far unsolved mystery of why a seemingly healthy baby dies suddenly, without warning and without apparent reason. A form of undiagnosed apnea has been suspected; various maternal risk factors, including cigarette smoking during pregnancy, maternal age less than 20 years, poor prenatal care, low weight gain, anemia, drug abuse and a history of sexually transmitted disease and/or urinary tract infection have all been suspected of heightening the likelihood of occurrence; and the presence of soft bedding materials and the breathing of second-hand smoke have also been cited as possible contributing factors. Recent studies at the National Institute of Child Health and Human Development (NICHD) have identified defects in the regions of the brains of SIDS-susceptible infants that control breathing. However, whatever the root cause of SIDS is eventually determined to be, it appears that pro-active parenting can substantially reduce the risk to the newborn.
More specifically, in 1992 the American Academy of Pediatrics recommended that babies be placed on their backs or sides to sleep, and subsequently modified this to recommend that babies be placed only on their backs to sleep. This recommendation was based on a number of studies conducted in Australia, New Zealand, Wales and elsewhere and was subsequently embraced by the NICHD as the cornerstone of a campaign called "Back to Sleep" launched in 1994. It is estimated that more than fifty percent of all SIDS deaths can be prevented if babies are prevented from maintaining a prone, face-down position during sleep; as mentioned, it also appears desirable to avoid the side-lying position.
Two approaches have been suggested to prevent SIDS or crib death. First, the infant can be denied the freedom to position itself in the dangerous face-down position--but this requires cumbersome and restrictive bedding, clothing or harnessing arrangements that introduce inconvenience, discomfort and perhaps a new set of hazards. The second approach involves monitoring the breathing of the infant so that a cessation of breathing can be timely recognized and intervention effected.
Two devices in the prior art suggest monitoring the breathing of an infant as a method of preventing SIDS, but differ in implementation. The device in U.S. Pat. No. 4,696,307 comprises a detection and signaling device attached to the body of the infant and responsive to the body displacements produced on the skin of the infant as it breathes. The breathing monitor of U.S. Pat. No. 5,400,012 proposes a fluid-filled bladder elastically attached to the infant to provide flexible and sensitive coupling between the infant and a breathing monitor including an LED and an alarm to report breathing and cessation of breathing respectively. The utility of both of these breathing monitors are limited by difficult attachment and delicate sensitivity issues presented when designing such sophisticated instrumentation for monitoring a tiny infant. Neither seems to have found a commercially viable niche.